Can't set an environment variable in a task

[deech]

I don't seem to be able to set an environment variable in a nimble task, am I missing something?

task t, "t":
   echo existsEnv("FOO")
   putEnv("FOO", "foo")
   echo getEnv("FOO")

Doing nimble t outputs:

false
          <-- note empty line

[genotrance]

putEnv isn't implemented in nimble's VM.

https://github.com/nim-lang/nimble/blob/master/src/nimblepkg/nimscriptsupport.nim

I had originally authored a PR for this.

nim-lang/nimble#541

My current idea is to remove the VM altogether and run nimble scripts through Nim. It is still TBD.

[Araq]

My current idea is to remove the VM altogether and run nimble scripts through Nim. It is still TBD.

If it helps to motivate you, I'm really looking forward to this! :-)

[dom96]

@genotrance I'm still skeptical about the performance of this. Sure, you can cache it but the performance will still be horrible when installing packages as most of them are going to be new. This won't be a problem for now when we don't have a lot of packages but in the future it'll become a massive scalability problem.

I would personally much rather push the nimscript evaluation to the Nim binary, this would free Nimble of this horrible dependency, which would have a number of advantages:

• Tons of compatibility problems: Nim and Nimble would not longer have a chance of diverging.
• There would be no issues introduced as a result of the Nim compiler evolving.
• Much smaller Nimble binaries
• This would be much faster than your approach

[genotrance]

This has been fixed in Nimble and works as expected now.